Gastric cancer Van Cutsem, Eric, Prof; Sagaert, Xavier, MD; Topal, Baki, Prof ...
The Lancet (British edition),
11/2016, Letnik:
388, Številka:
10060
Journal Article
Recenzirano
Summary Gastric cancer is one of the leading causes of cancer-related death worldwide. Many patients have inoperable disease at diagnosis or have recurrent disease after resection with curative ...intent. Gastric cancer is separated anatomically into true gastric adenocarcinomas and gastro-oesophageal-junction adenocarcinomas, and histologically into diffuse and intestinal types. Gastric cancer should be treated by teams of experts from different disciplines. Surgery is the only curative treatment. For locally advanced disease, adjuvant or neoadjuvant therapy is usually implemented in combination with surgery. In metastatic disease, outcomes are poor, with median survival being around 1 year. Targeted therapies, such as trastuzumab, an antibody against HER2 (also known as ERBB2), and the VEGFR-2 antibody ramucirumab, have been introduced. In this Seminar, we present an update of the causes, classification, diagnosis, and treatment of gastric cancer.
Summary Background Although trastuzumab plus chemotherapy is the standard of care for first-line treatment of HER2-positive advanced gastric cancer, there is no established therapy in the second-line ...setting. In GATSBY, we examined the efficacy and tolerability of trastuzumab emtansine in patients previously treated for HER2-positive advanced gastric cancer (unresectable, locally advanced, or metastatic gastric cancer, including adenocarcinoma of the gastro-oesophageal junction). Methods This is the final analysis from GATSBY, a randomised, open-label, adaptive, phase 2/3 study, done at 107 centres (28 countries worldwide). Eligible patients had HER2-positive advanced gastric cancer and progressed during or after first-line therapy. In stage one of the trial, patients were randomly assigned to treatment groups (2:2:1) to receive intravenous trastuzumab emtansine (3·6 mg/kg every 3 weeks or 2·4 mg/kg weekly) or physician's choice of a taxane (intravenous docetaxel 75 mg/m2 every 3 weeks or intravenous paclitaxel 80 mg/m2 weekly). In stage two, patients were randomly assigned to treatment groups (2:1) to receive the independent data monitoring committee (IDMC)-selected dose of trastuzumab emtansine (2·4 mg/kg weekly) or a taxane (same regimen as above). We used permuted block randomisation, stratified by world region, previous HER2-targeted therapy, and previous gastrectomy. The primary endpoint (overall survival) was assessed in the intention-to-treat population. This study is registered with ClinicalTrials.gov , number NCT01641939. Findings Between Sept 3, 2012, and Oct 14, 2013, 70 patients were assigned to receive trastuzumab emtansine 3·6 mg/kg every 3 weeks, 75 to receive trastuzumab emtansine 2·4 mg/kg weekly, and 37 to receive a taxane in the stage 1 part of the trial. At the pre-planned interim analysis (Oct 14, 2013), the IDMC selected trastuzumab emtansine 2·4 mg/kg weekly as the dose to proceed to stage 2. By Feb 9, 2015, a further 153 patients had been randomly assigned to receive trastuzumab emtansine 2·4 mg/kg weekly and a further 80 to receive a taxane. At data cutoff, median follow-up was 17·5 months (IQR 12·1–23·0) for the trastuzumab emtansine 2·4 mg/kg weekly group and 15·4 months (9·2–18·1) in the taxane group. Median overall survival was 7·9 months (95% CI 6·7–9·5) with trastuzumab emtansine 2·4 mg/kg weekly and 8·6 months (7·1–11·2) with taxane treatment (hazard ratio 1·15, 95% CI 0·87–1·51, one-sided p=0·86). The trastuzumab emtansine 2·4 mg/kg group had lower incidences of grade 3 or more adverse events (134 60% of 224 patients treated with trastuzumab emtansine vs 78 70% of 111 patients treated with a taxane), and similar incidences of adverse events leading to death (eight 4% vs four 4%), serious adverse events (65 29% vs 31 28%), and adverse events leading to treatment discontinuation (31 14% vs 15 14%) than did taxane treatment. The most common grade 3 or more adverse events in the trastuzumab emtansine 2·4 mg/kg weekly group were anaemia (59 26%) and thrombocytopenia (25 11%) compared with neutropenia (43 39%), and anaemia (20 18%), in the taxane group. The most common serious adverse events were anaemia (eight 4%), upper gastrointestinal haemorrhage (eight 4%), pneumonia (seven 3%), gastric haemorrhage (six 3%), and gastrointestinal haemorrhage (five 2%) in the trastuzumab emtansine 2·4 mg/kg weekly group compared with pneumonia (four 4%), febrile neutropenia (four 4%), anaemia (three 3%), and neutropenia (three 3%) in the taxane group. Interpretation Trastuzumab emtansine was not superior to taxane in patients with previously treated, HER2-positive advanced gastric cancer. There is still an unmet need in this patient group and therapeutic options remain limited. Funding F Hoffmann-La Roche.
Summary Background Everolimus, an oral inhibitor of the mammalian target of rapamycin (mTOR), has shown antitumour activity in patients with advanced pancreatic neuroendocrine tumours. We aimed to ...assess the combination of everolimus plus octreotide long-acting repeatable (LAR) in patients with low-grade or intermediate-grade neuroendocrine tumours (carcinoid). Methods We did a randomised, double-blind, placebo-controlled, phase 3 study comparing 10 mg per day oral everolimus with placebo, both in conjunction with 30 mg intramuscular octreotide LAR every 28 days. Randomisation was by interactive voice response systems. Participants were aged 18 years or older, with low-grade or intermediate-grade advanced (unresectable locally advanced or distant metastatic) neuroendocrine tumours, and disease progression established by radiological assessment within the past 12 months. Our primary endpoint was progression-free survival. Adjusted for two interim analyses, the prespecified boundary at final analysis was p≤0·0246. This study is registered at ClinicalTrials.gov , number NCT00412061. Findings 429 individuals were randomly assigned to study groups; 357 participants discontinued study treatment and one was lost to follow-up. Median progression-free survival by central review was 16·4 (95% CI 13·7–21·2) months in the everolimus plus octreotide LAR group and 11·3 (8·4–14·6) months in the placebo plus octreotide LAR group (hazard ratio 0·77, 95% CI 0·59–1·00; one-sided log-rank test p=0·026). Drug-related adverse events (everolimus plus octreotide LAR vs placebo plus octreotide LAR) were mostly grade 1 or 2, and adverse events of all grades included stomatitis (62% vs 14%), rash (37% vs 12%), fatigue (31% vs 23%), and diarrhoea (27% vs 16%). Interpretation Everolimus plus octreotide LAR, compared with placebo plus octreotide LAR, improved progression-free survival in patients with advanced neuroendocrine tumours associated with carcinoid syndrome. Funding Novartis Pharmaceuticals.
Summary Background VEGFR-2 has a role in gastric cancer pathogenesis and progression. We assessed whether ramucirumab, a monoclonal antibody VEGFR-2 antagonist, in combination with paclitaxel would ...increase overall survival in patients previously treated for advanced gastric cancer compared with placebo plus paclitaxel. Methods This randomised, placebo-controlled, double-blind, phase 3 trial was done at 170 centres in 27 countries in North and South America, Europe, Asia, and Australia. Patients aged 18 years or older with advanced gastric or gastro-oesophageal junction adenocarcinoma and disease progression on or within 4 months after first-line chemotherapy (platinum plus fluoropyrimidine with or without an anthracycline) were randomly assigned with a centralised interactive voice or web-response system in a 1:1 ratio to receive ramucirumab 8 mg/kg or placebo intravenously on days 1 and 15, plus paclitaxel 80 mg/m2 intravenously on days 1, 8, and 15 of a 28-day cycle. A permuted block randomisation, stratified by geographic region, time to progression on first-line therapy, and disease measurability, was used. The primary endpoint was overall survival. Efficacy analysis was by intention to treat, and safety analysis included all patients who received at least one treatment with study drug. This trial is registered with ClinicalTrials.gov , number NCT01170663 , and has been completed; patients who are still receiving treatment are in the extension phase. Findings Between Dec 23, 2010, and Sept 23, 2012, 665 patients were randomly assigned to treatment—330 to ramucirumab plus paclitaxel and 335 to placebo plus paclitaxel. Overall survival was significantly longer in the ramucirumab plus paclitaxel group than in the placebo plus paclitaxel group (median 9·6 months 95% CI 8·5–10·8 vs 7·4 months 95% CI 6·3–8·4, hazard ratio 0·807 95% CI 0·678–0·962; p=0·017). Grade 3 or higher adverse events that occurred in more than 5% of patients in the ramucirumab plus paclitaxel group versus placebo plus paclitaxel included neutropenia (133 41% of 327 vs 62 19% of 329), leucopenia (57 17% vs 22 7%), hypertension (46 14% vs eight 2%), fatigue (39 12% vs 18 5%), anaemia (30 9% vs 34 10%), and abdominal pain (20 6% vs 11 3%). The incidence of grade 3 or higher febrile neutropenia was low in both groups (ten 3% vs eight 2%). Interpretation The combination of ramucirumab with paclitaxel significantly increases overall survival compared with placebo plus paclitaxel, and could be regarded as a new standard second-line treatment for patients with advanced gastric cancer. Funding Eli Lilly and Company.
Summary Background Bevacizumab plus fluoropyrimidine-based chemotherapy is standard treatment for first-line and bevacizumab-naive second-line metastatic colorectal cancer. We assessed continued use ...of bevacizumab plus standard second-line chemotherapy in patients with metastatic colorectal cancer progressing after standard first-line bevacizumab-based treatment. Methods In an open-label, phase 3 study in 220 centres in Austria, Belgium, Czech Republic, Denmark, Estonia, Finland, France, Germany, the Netherlands, Norway, Portugal, Saudi Arabia, Spain, Sweden, and Switzerland, patients (aged ≥18 years) with unresectable, histologically confirmed metastatic colorectal cancer progressing up to 3 months after discontinuing first-line bevacizumab plus chemotherapy were randomly assigned in a 1:1 ratio to second-line chemotherapy with or without bevacizumab 2·5 mg/kg per week equivalent (either 5 mg/kg every 2 weeks or 7·5 mg/kg every 3 weeks, intravenously). The choice between oxaliplatin-based or irinotecan-based second-line chemotherapy depended on the first-line regimen (switch of chemotherapy). A combination of a permuted block design and the Pocock and Simon minimisation algorithm was used for the randomisation. The primary endpoint was overall survival, analysed by intention to treat. This trial is registered with ClinicalTrials.gov , number NCT00700102. Findings Between Feb 1, 2006, and June 9, 2010, 409 (50%) patients were assigned to bevacizumab plus chemotherapy and 411 (50%) to chemotherapy alone. Median follow-up was 11·1 months (IQR 6·4–15·6) in the bevacizumab plus chemotherapy group and 9·6 months (5·4–13·9) in the chemotherapy alone group. Median overall survival was 11·2 months (95% CI 10·4–12·2) for bevacizumab plus chemotherapy and 9·8 months (8·9–10·7) for chemotherapy alone (hazard ratio 0·81, 95% CI 0·69–0·94; unstratified log-rank test p=0·0062). Grade 3–5 bleeding or haemorrhage (eight 2% vs one <1%), gastrointestinal perforation (seven 2% vs three <1%), and venous thromboembolisms (19 5% vs 12 3%) were more common in the bevacizumab plus chemotherapy group than in the chemotherapy alone group. The most frequently reported grade 3–5 adverse events were neutropenia (65 16% in the bevacizumab and chemotherapy group vs 52 13% in the chemotherapy alone group), diarrhoea (40 10% vs 34 8%, respectively), and asthenia (23 6% vs 17 4%, respectively). Treatment-related deaths were reported for four patients in the bevacizumab plus chemotherapy group and three in the chemotherapy alone group. Interpretation Maintenance of VEGF inhibition with bevacizumab plus standard second-line chemotherapy beyond disease progression has clinical benefits in patients with metastatic colorectal cancer. This approach is also being investigated in other tumour types, including metastatic breast and non-small cell lung cancers. Funding F Hoffmann-La Roche.
Summary Background Bevacizumab improves the efficacy of oxaliplatin-based chemotherapy in metastatic colorectal cancer. Our aim was to assess the use of bevacizumab in combination with ...oxaliplatin-based chemotherapy in the adjuvant treatment of patients with resected stage III or high-risk stage II colon carcinoma. Methods Patients from 330 centres in 34 countries were enrolled into this phase 3, open-label randomised trial. Patients with curatively resected stage III or high-risk stage II colon carcinoma were randomly assigned (1:1:1) to receive FOLFOX4 (oxaliplatin 85 mg/m2 , leucovorin 200 mg/m2 , and fluorouracil 400 mg/m2 bolus plus 600 mg/m2 22-h continuous infusion on day 1; leucovorin 200 mg/m2 plus fluorouracil 400 mg/m2 bolus plus 600 mg/m2 22-h continuous infusion on day 2) every 2 weeks for 12 cycles; bevacizumab 5 mg/kg plus FOLFOX4 (every 2 weeks for 12 cycles) followed by bevacizumab monotherapy 7·5 mg/kg every 3 weeks (eight cycles over 24 weeks); or bevacizumab 7·5 mg/kg plus XELOX (oxaliplatin 130 mg/m2 on day 1 every 2 weeks plus oral capecitabine 1000 mg/m2 twice daily on days 1–15) every 3 weeks for eight cycles followed by bevacizumab monotherapy 7·5 mg/kg every 3 weeks (eight cycles over 24 weeks). Block randomisation was done with a central interactive computerised system, stratified by geographic region and disease stage. Surgery with curative intent occurred 4–8 weeks before randomisation. The primary endpoint was disease-free survival, analysed for all randomised patients with stage III disease. This study is registered with ClinicalTrials.gov , number NCT00112918. Findings Of the total intention-to-treat population (n=3451), 2867 patients had stage III disease, of whom 955 were randomly assigned to receive FOLFOX4, 960 to receive bevacizumab–FOLFOX4, and 952 to receive bevacizumab–XELOX. After a median follow-up of 48 months (range 0–66 months), 237 patients (25%) in the FOLFOX4 group, 280 (29%) in the bevacizumab–FOLFOX4 group, and 253 (27%) in the bevacizumab–XELOX group had relapsed, developed a new colon cancer, or died. The disease-free survival hazard ratio for bevacizumab–FOLFOX4 versus FOLFOX4 was 1·17 (95% CI 0·98–1·39; p=0·07), and for bevacizumab–XELOX versus FOLFOX4 was 1·07 (0·90–1·28; p=0·44). After a minimum follow-up of 60 months, the overall survival hazard ratio for bevacizumab–FOLFOX4 versus FOLFOX4 was 1·27 (1·03–1·57; p=0·02), and for bevacizumab–XELOX versus FOLFOX4 was 1·15 (0·93–1·42; p=0·21). The 573 patients with high-risk stage II cancer were included in the safety analysis. The most common grade 3–5 adverse events were neutropenia (FOLFOX4: 477 42% of 1126 patients, bevacizumab-FOLFOX4: 416 36% of 1145 patients, and bevacizumab–XELOX: 74 7% of 1135 patients), diarrhoea (110 10%, 135 12%, and 181 16%, respectively), and hypertension (12 1%, 122 11%, and 116 10%, respectively). Serious adverse events were more common in the bevacizumab groups (bevacizumab–FOLFOX4: 297 26%; bevacizumab–XELOX: 284 25%) than in the FOLFOX4 group (226 20%). Treatment-related deaths were reported in one patient receiving FOLFOX4, two receiving bevacizumab–FOLFOX4, and five receiving bevacizumab–XELOX. Interpretation Bevacizumab does not prolong disease-free survival when added to adjuvant chemotherapy in resected stage III colon cancer. Overall survival data suggest a potential detrimental effect with bevacizumab plus oxaliplatin-based adjuvant therapy in these patients. On the basis of these and other data, we do not recommend the use of bevacizumab in the adjuvant treatment of patients with curatively resected stage III colon cancer. Funding Genentech, Roche, and Chugai.
Summary Background Previous results of the EORTC intergroup trial 40983 showed that perioperative chemotherapy with FOLFOX4 (folinic acid, fluorouracil, and oxaliplatin) increases progression-free ...survival (PFS) compared with surgery alone for patients with initially resectable liver metastases from colorectal cancer. Here we present overall survival data after long-term follow-up. Methods This randomised, controlled, parallel-group, phase 3 study recruited patients from 78 hospitals across Europe, Australia, and Hong Kong. Eligible patients aged 18–80 years who had histologically proven colorectal cancer and up to four liver metastases were randomly assigned (1:1) to either perioperative FOLFOX4 or surgery alone. Perioperative FOLFOX4 consisted of six 14-day cycles of oxaliplatin 85mg/m2 , folinic acid 200 mg/m2 (DL form) or 100 mg/m2 (L form) on days 1–2 plus bolus, and fluorouracil 400 mg/m2 (bolus) and 600 mg/m2 (continuous 22 h infusion), before and after surgery. Patients were centrally randomised by minimisation, adjusting for centre and risk score and previous adjuvant chemotherapy to primary surgery for colorectal cancer, and the trial was open label. Analysis of overall survival was by intention to treat in all randomly assigned patients. This trial is registered with ClinicalTrials.gov , number NCT00006479. Findings Between Oct 10, 2000, and July 5, 2004, 364 patients were randomly assigned to a treatment group (182 patients in each group, of which 171 per group were eligible and 152 per group underwent resection). At a median follow-up of 8·5 years (IQR 7·6–9·5), 107 (59%) patients in the perioperative chemotherapy group had died versus 114 (63%) in the surgery-only group (HR 0·88, 95% CI 0·68–1·14; p=0·34). In all randomly assigned patients, median overall survival was 61·3 months (95% CI 51·0–83·4) in the perioperative chemotherapy group and 54·3 months (41·9–79·4) in the surgery alone group. 5-year overall survival was 51·2% (95% CI 43·6–58·3) in the perioperative chemotherapy group versus 47·8% (40·3–55·0) in the surgery-only group. Two patients in the perioperative chemotherapy group and three in the surgery-only group died from complications of protocol surgery, and one patient in the perioperative chemotherapy group died possibly as a result of toxicity of protocol treatment. Interpretation We found no difference in overall survival with the addition of perioperative chemotherapy with FOLFOX4 compared with surgery alone for patients with resectable liver metastases from colorectal cancer. However, the previously observed benefit in PFS means that perioperative chemotherapy with FOLFOX4 should remain the reference treatment for this population of patients. Funding Norwegian and Swedish Cancer Societies, Cancer Research UK, Ligue Nationale Contre Cancer, US National Cancer Institute, Sanofi-Aventis.
Summary Background Tumour mutational status is an important determinant of the response of metastatic colorectal cancer to targeted treatments. However, the genotype of the tissue obtained at the ...time of diagnosis might not accurately represent tumour genotype after multiple lines of treatment. This retrospective exploratory analysis investigated the clinical activity of regorafenib in biomarker subgroups of the CORRECT study population defined by tumour mutational status or plasma protein levels. Methods We used BEAMing technology to identify KRAS, PIK3CA , and BRAF mutations in DNA obtained from the plasma of 503 patients with metastatic colorectal cancer who enrolled in the CORRECT trial. We quantified total human genomic DNA isolated from plasma samples for 503 patients using a modified version of human long interspersed nuclear element-1 (LINE-1) quantitive real-time PCR. We also measured the concentration of 15 proteins of interest—angiopoietin 2, interleukin 6, interleukin 8, placental growth factor, soluble TIE-1, soluble VEGFR1, VEGF-A, VEGF-C, VEGF-D, VEGF-A isoform 121, bone morphogenetic protein 7, macrophage colony-stimulating factor, stromal cell-derived factor-1, tissue inhibitor of metalloproteinase 2, and von Willebrand factor—in plasma samples from 611 patients. We did correlative analyses of overall survival and progression-free survival in patient subgroups based on mutational status, circulating DNA concentration, and protein concentrations. The CORRECT trial was registered with ClinicalTrials.gov , number NCT01103323. Findings Tumour-associated mutations were readily detected with BEAMing of plasma DNA, with KRAS mutations identified in 349 (69%) of 503 patients, PIK3CA mutations in 84 (17%) of 503 patients, and BRAF mutations in 17 (3%) of 502 patients. We did not do correlative analysis based on BRAF genotype because of the low mutational frequency detected for this gene. Some of the most prevalent individual hot-spot mutations we identified included: KRAS ( KRAS G12D, 116 28% of 413 mutations; G12V, 72 17%; and G13D, 67 16%) and PIK3CA ( PIK3CA E542K, 27 30% of 89 mutations; E545K, 37 42%; and H1047R, 12 14%). 41 (48%) of 86 patients who had received anti-EGFR therapy and whose archival tumour tissue DNA was KRAS wild-type in BEAMing analysis were identified as having KRAS mutations in BEAMing analysis of fresh plasma DNA. Correlative analyses suggest a clinical benefit favouring regorafenib across patient subgroups defined by KRAS and PIK3CA mutational status (progression-free survival with regorafenib vs placebo: hazard ratio HR 0·52, 95% CI 0·35–0·76 for KRAS wild-type; HR 0·51, 95% CI 0·40–0·65 for KRAS mutant KRAS wild type vs mutant, pinteraction =0·74; HR 0·50, 95% CI 0·40–0·63 for PIK3CA wild-type; HR 0·54, 95% CI 0·32–0·89 for PIK3CA mutant PIK3CA wild-type vs mutant, pinteraction =0·85) or circulating DNA concentration (progression-free survival with regorafenib vs placebo: HR 0·53, 95% CI 0·40–0·71, for low circulating DNA concentrations; HR 0·52, 95% CI 0·40–0·70, for high circulating DNA concentrations; low vs high circulating DNA, pinteraction =0·601). With the exception of von Willebrand factor, assessed with the median cutoff method, plasma protein concentrations were also not associated with regorafenib activity in terms of progression-free survival. In univariable analyses, the only plasma protein that was associated with overall survival was TIE-1, high concentrations of which were associated with longer overall survival compared with low TIE-1 concentrations. This association was not significant in multivariable analyses. Interpretation BEAMing of circulating DNA could be a viable approach for non-invasive analysis of tumour genotype in real time and for the identification of potentially clinically relevant mutations that are not detected in archival tissue. Additionally, the results show that regorafenib seems to be consistently associated with a clinical benefit in a range of patient subgroups based on mutational status and protein biomarker concentrations. Funding Bayer HealthCare Pharmaceuticals.
Summary Background Angiogenesis is an important therapeutic target in colorectal carcinoma. Ramucirumab is a human IgG-1 monoclonal antibody that targets the extracellular domain of VEGF receptor 2. ...We assessed the efficacy and safety of ramucirumab versus placebo in combination with second-line FOLFIRI (leucovorin, fluorouracil, and irinotecan) for metastatic colorectal cancer in patients with disease progression during or after first-line therapy with bevacizumab, oxaliplatin, and a fluoropyrimidine. Methods Between Dec 14, 2010, and Aug 23, 2013, we enrolled patients into the multicentre, randomised, double-blind, phase 3 RAISE trial. Eligible patients had disease progression during or within 6 months of the last dose of first-line therapy. Patients were randomised (1:1) via a centralised, interactive voice-response system to receive 8 mg/kg intravenous ramucirumab plus FOLFIRI or matching placebo plus FOLFIRI every 2 weeks until disease progression, unacceptable toxic effects, or death. Randomisation was stratified by region, KRAS mutation status, and time to disease progression after starting first-line treatment. The primary endpoint was overall survival in the intention-to-treat population. This study is registered with ClinicalTrials.gov , number NCT01183780 .ld Findings We enrolled 1072 patients (536 in each group). Median overall survival was 13·3 months (95% CI 12·4–14·5) for patients in the ramucirumab group versus 11·7 months (10·8–12·7) for the placebo group (hazard ratio 0·844 95% CI 0·730–0·976; log-rank p=0·0219). Survival benefit was consistent across subgroups of patients who received ramucirumab plus FOLFIRI. Grade 3 or worse adverse events seen in more than 5% of patients were neutropenia (203 38% of 529 patients in the ramucirumab group vs 123 23% of 528 in the placebo group, with febrile neutropenia incidence of 18 3% vs 13 2%), hypertension (59 11% vs 15 3%), diarrhoea (57 11% vs 51 10%), and fatigue (61 12% vs 41 8%). Interpretation Ramucirumab plus FOLFIRI significantly improved overall survival compared with placebo plus FOLFIRI as second-line treatment for patients with metastatic colorectal carcinoma. No unexpected adverse events were identified and toxic effects were manageable. Funding Eli Lilly.
Summary Background Trastuzumab, a monoclonal antibody against human epidermal growth factor receptor 2 (HER2; also known as ERBB2), was investigated in combination with chemotherapy for first-line ...treatment of HER2-positive advanced gastric or gastro-oesophageal junction cancer. Methods ToGA (Trastuzumab for Gastric Cancer) was an open-label, international, phase 3, randomised controlled trial undertaken in 122 centres in 24 countries. Patients with gastric or gastro-oesophageal junction cancer were eligible for inclusion if their tumours showed overexpression of HER2 protein by immunohistochemistry or gene amplification by fluorescence in-situ hybridisation. Participants were randomly assigned in a 1:1 ratio to receive a chemotherapy regimen consisting of capecitabine plus cisplatin or fluorouracil plus cisplatin given every 3 weeks for six cycles or chemotherapy in combination with intravenous trastuzumab. Allocation was by block randomisation stratified by Eastern Cooperative Oncology Group performance status, chemotherapy regimen, extent of disease, primary cancer site, and measurability of disease, implemented with a central interactive voice recognition system. The primary endpoint was overall survival in all randomised patients who received study medication at least once. This trial is registered with ClinicalTrials.gov , number NCT01041404. Findings 594 patients were randomly assigned to study treatment (trastuzumab plus chemotherapy, n=298; chemotherapy alone, n=296), of whom 584 were included in the primary analysis (n=294; n=290). Median follow-up was 18·6 months (IQR 11–25) in the trastuzumab plus chemotherapy group and 17·1 months (9–25) in the chemotherapy alone group. Median overall survival was 13·8 months (95% CI 12–16) in those assigned to trastuzumab plus chemotherapy compared with 11·1 months (10–13) in those assigned to chemotherapy alone (hazard ratio 0·74; 95% CI 0·60–0·91; p=0·0046). The most common adverse events in both groups were nausea (trastuzumab plus chemotherapy, 197 67% vs chemotherapy alone, 184 63%), vomiting (147 50% vs 134 46%), and neutropenia (157 53% vs 165 57%). Rates of overall grade 3 or 4 adverse events (201 68% vs 198 68%) and cardiac adverse events (17 6% vs 18 6%) did not differ between groups. Interpretation Trastuzumab in combination with chemotherapy can be considered as a new standard option for patients with HER2-positive advanced gastric or gastro-oesophageal junction cancer. Funding F Hoffmann-La Roche.